Another link. posted by DVDBURN (MD) on June 06, 2012 at 11:42 PM
These links are most impressive although I have to admit it's mostly greek to me (I'm not an EE), but I get the gist. So not only is it ineffective to ground the knock sensor sub-harness shielding but it's potentially detrimental to the ECU discriminating knock signals correctly. That's not obvious and rather counter intuitive. The example in the first link describing the dreaded ground loop seems very relevant since the triaxial accelerometers measurement and our knock system probably have many characteristics in common. The more I learn about this stuff the more I realize the stock Z32 control system has a lot more going on than simple table reads. I imagine you came across this doing your ground (breaking) ECU research. Thanks a ton for the support and links Gary.